EP1527994B1 - Environmental control system and method of conditioning air for the climatisation of a space - Google Patents

Description

The invention relates to an air conditioning system, in particular an air conditioning system for air conditioning a passenger cabin of an aircraft according to the preamble of claim 1. The invention further relates to a method for the treatment of air for the air conditioning of a room, in particular for the air conditioning of a passenger cabin of an aircraft.

Air conditioning systems for aircraft are known in numerous different embodiments. They are used in particular for heating and cooling the cabin, the cabin pressure and the fresh air supply. It is important that the air conditioning system has the smallest possible size and weight, which is of great interest, in particular in aircraft construction. Prior art air conditioning systems generally have a shaft device comprising a compressor and a turbine, which may additionally be provided with a fan arranged in a ram air duct. In the ram air channel are in prior art systems, one or more heat exchangers, which are used for cooling of the engines or auxiliary equipment bled compressed air serve. In prior systems, the compressed air is first cooled in a first heat exchanger in the ram air channel, then compressed in the compressor of the shaft device, cooled in a second, arranged in the ram air duct heat exchanger and then fed to a Wasserabscheidekreislauf. Subsequently, the air dehumidified in this way flows through the turbine of the shaft device and is then fed to a mixing chamber or the passenger cabin.

There are known air conditioning systems in which two of the said systems are provided for redundancy reasons. Embodiments are also known in which not all components are duplicated, but only those which have a relatively large selection probability. Such an air conditioning system, in which the shaft devices are present twice, the ram air heat exchanger and the Wasserabscheidekreislauf but only simply, is from the EP 0 891 279 B1 known.

A development of the known from this document system is the subject of DE 102 01 426 , The air conditioning system disclosed in this document has at least one arranged in a ram air duct heat exchanger for cooling compressed air. The heat exchanger comprises at least a first and a second heat exchanger unit separated therefrom on the compressed air side, of which in each case one compressed air side communicates with one of the shaft devices in each case. The shaft devices have compressors which are connected on the outlet side to the compressed air side inlet of the heat exchanger units separated on the compressed air side. The heat exchanger units each have their own compressed air supply.

For the at least two heat exchanger units, a common ram air inlet duct and ram air outlet ducts separate from each other in terms of flow mechanics are provided.

By in the DE 102 01 426 A1 disclosed air conditioning system is achieved a particularly compact and at the same time reliable, redundant and inexpensive arrangement.

In the air conditioning system described above, the compressed air supplied to the system is extracted from the engines. The tapping of the fresh air to be treated directly from the engine, however, is problematic in that with the bleeding of the air from the engine usually an undesirable reduction in engine performance is connected.

Out US 4,523,517 A4 An air conditioning system according to the preamble of claim 1 is known. It is provided that the compressor on the inlet side with congestion or ambient air are applied and that one or more motors are provided, by means of which the compressor can be driven. Thus, according to the invention, the compressors are not supplied with air drawn from the engines, but only with accumulated air, which is compressed in the compressors and then supplied to the respective heat exchanger unit. In this case, one or more motors are provided by means of which the compressor can be driven. The motors are required to supplement the power of the compressors provided by one expansion stage or to ensure compressor operation in the case of bypass of the expansion stage.

Such an air conditioning system has the advantage that it manages without any bleed air from the engines. The system is only supplied with storage or ambient air, both as air to be conditioned for air conditioning of the room and as a cooling medium for the air to be treated.

In this system, however, the water separator is arranged in the low-pressure region behind the turbine, which entails the disadvantage that the turbine outlet temperature must be above 0 ° C. This results in the disadvantage that in order to ensure the same cooling capacity, a larger mass flow must be managed, which in turn leads to the fact that the turbine builds comparatively large, which is undesirable. In addition, the cooling required in the ground operation must be provided by a separate system, while the compressor only allows ventilation of the cabin, since the humid air on the ground would otherwise freeze the turbine. Thus, the components of the system can only be used insufficiently.

It is therefore an object of the present invention to further develop an air conditioning system according to the preamble of claim 1, that the disadvantages of the prior art are avoided and that all system components can be optimally utilized.

This object is achieved by an air conditioning system with the features according to claim 1 and a method for the treatment of air for air conditioning a room with the features of claim 22. In this case, the turbine according to the invention is preceded by a water separator, the turbine bypass line bypassing both the water separator and the turbine on the compressed air side.

Advantageous embodiments of the invention are the subject of the dependent claims.

In a further embodiment of the invention, an air conditioning system having at least one arranged in a ram air duct heat exchanger for cooling compressed air and at least a first and a second shaft means, wherein the heat exchanger comprises at least a first and one of the compressed air side separate second heat exchanger unit in the common ram air channel are arranged and each of which is a compressed air side with one of the shaft means in communication, the shaft means having compressors which are on the outlet side each with the compressed air side inlet of the heat exchanger units in communication, the compressor on the inlet side with congestion or ambient air are applied and that or a plurality of motors are provided, by means of which the compressors are drivable.

In a further embodiment of the invention, it is provided that the heat exchanger units form a structural unit. They are arranged in the common ram air channel.

It can be provided that a common ram air inlet channel is provided for the at least two heat exchanger units, wherein for the purpose of changing the ram air flow and thus the cooling capacity of the heat exchanger units can be provided in their position adjustable ram air duct inlet flap.

In a further embodiment of the invention, a common ram air outlet channel is provided for the at least two heat exchanger units. In this one, two or more motor-driven blower can be provided. These ensure in ground operation for maintaining a flow through the ram air duct and ensure the cooling capacity of the arranged in the ram air duct heat exchanger units. It is also possible to provide separate ram air outlet channels for the at least two heat exchanger units. In this case, one or preferably two or more motor-driven blowers can be arranged in each of the separate ram air outlet ducts starting directly on the outlet side of the heat exchanger units.

The blowers can be arranged in flow-mechanically separate sections of the ram air outlet channel. This fluid-mechanical separation of the ram air outlet duct preferably relates only to a partial area of the ram air outlet duct and advantageously not to the area directly adjoining the heat exchanger units. In order to prevent that in case of failure of one of the fans, the fan in operation promotes air over the stationary fan and not through the heat exchanger units can be provided be provided downstream of the blower check valves, which prevent that in the supplied by the blower portions of the ram air outlet channel, a back flow takes place.

In order to increase the permeability of the ram air duct, it may be provided that one or more blower bypasses, also provided with check valves, are arranged in the ram air duct. At least one bypass can be arranged, for example, between the sections of the ram air outlet duct supplied by the respective blowers.

In a further embodiment of the invention, it is provided that the compressors are multi-stage compressors, of which the first stage is acted upon inlet side with congestion or ambient air and the last stage is on the outlet side with the compressed air side inlet of the heat exchanger units in communication. For example, two-stage or multi-stage compressors can be used.

The shaft means may comprise at least one compressor, a turbine as a relaxation stage and a motor. The motor for driving the compressor is thus preferably part of a shaft device.

In a further embodiment of the invention, each of the shaft devices is in each case associated with a Wasserabscheidekreislauf. The Wasserabscheidekreisläufe serve to dehumidify the relaxation stage supplied air. In principle, it can also be provided that a common Wasserabscheidekreislauf is provided for the plurality of shaft means.

Especially at high altitudes, it may be necessary not to guide the air flowing from the heat exchanger unit on the compressed air side through the Wasserabscheidekreislauf and the expansion stage in order to ensure sufficient permeability of the system and to ensure that the compressor power is sufficient to ensure sufficient Kabinenbedruckung. In this case, the cooling capacity is not due to the expansion stage, but in the essentially provided by the heat exchanger unit. A bypass of Wasserabscheidekreislaufes is possible because the air at relatively high altitudes is relatively dry and water separation is therefore not mandatory. In order to ensure sufficient cooling of the cabin air, in particular in this case, it may additionally be provided that a cabin air circuit is operated, in which means for removing heat from the circulated air are arranged. The means for removing heat can be carried out arbitrarily. They may comprise a heat exchanger or an evaporator, are passed through the appropriate coolant.

It is particularly advantageous if the heat exchanger has a further, can be acted upon with congestion or ambient heat exchanger unit which is not in communication with the first and the second heat exchanger unit on the compressed air side. This heat exchanger unit can be designed as a condenser and communicate with the evaporator. The evaporator and the condenser may be components of a closed coolant circuit.

In a further embodiment of the invention, one or more bypass lines extending from the outlet side of the heat exchanger units to the outlet side of the expansion stages are provided, which can each be shut off by means of a valve arranged therein. The bypass lines serve to increase the permeability of the system at high altitudes. In this mode of operation, it may be necessary to make a bypass, in particular of the water separation circuit and / or the turbine, in order to minimize the pressure loss of the compressor outlet air. In this case, the air cooled in the heat exchanger units is preferably fed by means of the bypass downstream of the turbine, preferably downstream of the condenser of the Wasserabscheidekreislaufes and then fed to a mixing chamber or the passenger cabin.

In a further embodiment of the invention, the turbine is on the inlet side via a closable with a valve line with the cabin or one of these upstream mixing chamber and the outlet side via a closable with a valve Line with the environment in connection, means are provided, through which the turbine of the compressed air in the compressor lines can be shut off. The means may be implemented as valves arranged in the inlet line connecting the turbine to the water separation circuit and in the outlet line connecting the turbine to the mixing chamber or the cabin.

The present invention further relates to a method for the treatment of air for the air conditioning of a room, in particular for the air conditioning of a passenger cabin of an aircraft according to claim 22. In a first mode of operation, the air cooled in the heat exchanger units is fed to a Wasserabscheidekreislauf, relaxed in a relaxation stage and in the air-conditioned room or an upstream mixing chamber out. In particular, at high altitudes, it is provided in a second operating mode that the air cooled in the heat exchanger units, bypassing the Wasserabscheidekreislaufes and / or the expansion stage is performed directly in the room to be conditioned or an upstream mixing chamber.

As stated above, the first operating mode is preferably to be used in ground operation or at lower altitudes and the second operating mode is preferably to be used at higher altitudes.

The cooling capacity for cooling the air supplied to the heat exchanger units by means of storage or ambient air can be controlled or regulated by changing the position of a ram air duct inlet flap and / or by changing the operation of blowers arranged in the ram air outlet duct.

To increase the cooling capacity can be provided that the cabin air is at least partially recycled and this is subjected to a cooling process. It is provided in an advantageous embodiment of the method that the cooling takes place by means of a cooling medium, which is guided in the circuit, wherein the cooling medium in a in the ram air duct of the air conditioning system arranged heat exchanger unit is removed heat. It can be provided that the temperature and pressure conditions are selected such that the cooling medium condenses in the heat exchanger unit. In order to utilize the energy content of the cabin air, it can be provided in a further embodiment of the invention that in the second operating mode cabin air is expanded via the turbine and then supplied to the ambient air.

The invention further relates to an air conditioning system, in particular an air conditioning system for air conditioning a passenger cabin of an aircraft with at least one arranged in a ram air duct heat exchanger with at least one side connected to the heat exchanger pressure air side shaft device with at least one on the inlet side with congestion or ambient air acted upon compressor and at least one turbine with at least one motor for driving the compressor, with a turbine bypass line for bypassing the turbine on the compressed air side, and with at least one control device, by means of which the air conditioning system is operable in a first operating mode, in which the compressed air in the turbine is expanded, and in a second mode of operation is operable in which the compressed air is predominantly or completely passed through the turbine bypass line, wherein the control device is in communication with the engine and such is carried out that the engine is operated in the first operating mode such that the engine power is used for cooling purposes as well as for printing, and is operated in the second operating mode such that the engine power is used to compress the congestion or ambient air.

It can be provided that the first operating mode is applied in ground operation or at low altitudes and the second mode of operation, on the other hand, greater altitudes.

In a preferred embodiment of the invention, the air conditioning system is designed according to one of claims 1 to 21.

Such an air conditioning system has the advantage that the available engine power of the compressor engine is not largely unused, especially in ground operation or at lower altitudes, but predominantly or exclusively for cooling and for printing the cabin, i. is used to compress the accumulation or ambient air. For example, the engine can operate in the range of 80-100% of its maximum power. The cooling is achieved by the relaxation of the correspondingly compressed air in the turbine of the shaft device. At higher altitudes, the available engine power is substantially or exclusively used to compress the ambient air to the cabin pressure level, i. used for cabin printing. Cooling in flight takes place through the stagnation air heat exchanger and through optional recirculation cooling.

The air conditioning system has the advantage that the power of the compressor motor is also used in ground operation or at lower altitudes predominantly or exclusively for cooling, so that the apparent from Fig. 2 cabin vent circuits 100 can be performed with a correspondingly reduced cooling capacity. Another advantage results from the fact that in the first operating mode, a water separation circuit upstream of the turbine can be used, so that, for example, dehumidification is also possible in ground operation.

The invention further relates to a method for the treatment of air for the air conditioning of a room, in particular for the air conditioning of a passenger cabin of an aircraft, comprising the following steps: compressing ambient or ram air in a driven by a motor compressor unit and supply of the compressed air in a heat exchanger, Cooling of the air supplied to the heat exchanger by congestion or ambient air, wherein in a first mode of operation, the air cooled in the heat exchanger is expanded in a flash stage, wherein in a second mode of operation, the air cooled in the heat exchanger is predominantly or completely bypassed in the bypass to the expansion stage , and in the first operating mode, the engine power is used for cooling purposes and for printing and in the second operating mode the engine power is used to compress the accumulated or ambient air.

In the first operating mode, it may be provided that the cooling of the air takes place by means of the ram air heat exchanger or by the expansion of the compressed air in the turbine. In the second operating mode, it can be provided that the cooling of the air takes place by means of the ram air heat exchanger or by means of circulating air cooling.

It can be provided that in the first operating mode, the available engine power is used predominantly or exclusively for cooling purposes and for printing the cabin or any other space to be printed and that in the second operating mode, the available engine power predominantly or exclusively for printing, i. is used to compress the ambient or ram air to the level of the space to be printed, in particular the cabin.

The available engine power may, in a further embodiment of the invention, correspond to the value of the engine power to be applied by the engine at maximum altitude when the turbine is bypassed, i. not available to drive the compressor. In a preferred embodiment of the invention, this operating state determines the design of the compressor motor.

In prior art systems, the power available per se of the compressor motor in ground operation and low altitudes is largely unused. In a preferred embodiment of the invention it is provided that the engine is operated in ground operation with over 50%, preferably with over 70% and more preferably in the range 70-80% of the available engine power.

The method may be configured according to one of claims 22 to 29.

Fig. 1:

eine schematische Darstellung eines Klimatisierungssystems gemäß der Erfindung,

Fig. 2:

eine schematische Darstellung einer Klimatisierungsanlage mit zwei Klimatisierungssystemen gemäß Fig. 1,

Fig. 3a:

eine schematische Darstellung des Klimatisierungssystems gemäß Fig. 1 in einem ersten Betriebsmodus,

Fig. 3b:

eine schematische Darstellung des Klimatisierungssystems gemäß Fig. 1 in einem zweiten Betriebsmodus,

Fig. 4:

eine schematische Darstellung eines Klimatisierungssystems gemäß der Erfindung mit Nutzung der Kabinenabluft und

Fig. 5:

eine schematische Darstellung eines Klimatisierungssystems gemäß der Erfindung mit drei Stauluftwärmetauschern und drei Welleneinrichtungen.

Further details and advantages of the invention will be explained with reference to an embodiment shown in the drawing. Show it:

Fig. 1:

a schematic representation of an air conditioning system according to the invention,

Fig. 2:

1 is a schematic representation of an air conditioning system with two air conditioning systems according to FIG. 1, FIG.

Fig. 3a:

1 is a schematic representation of the air conditioning system according to FIG. 1 in a first operating mode,

3b:

1 is a schematic representation of the air conditioning system according to FIG. 1 in a second operating mode, FIG.

4:

a schematic representation of an air conditioning system according to the invention with use of the cabin exhaust air and

Fig. 5:

a schematic representation of an air conditioning system according to the invention with three ram air heat exchangers and three shaft devices.

Fig. 1 shows a schematic representation of an air conditioning system with two motorized shaft means 20, 30, each consisting of a two-stage compressor 22, 32 of a turbine 24, 34 and an electric motor 26, 36 for supplementary drive of the compressors 22, 32 consist. The shaft means are provided in the figures with the name MACM.

The air conditioning system also has a common ram air duct 40, in which the heat exchanger units 12, 14, which are separated from one another on the compressed air side, are arranged, which are also designated in the figures by the designations MHX1 and MHX2. Between the heat exchanger units separated on the compressed air side 12, 14 there is a further heat exchanger unit 16, which is not connected to any of the heat exchanger units 12 or 14 on the compressed air side and which is also designated in the figures by the designations VCHX and VCCon. The further heat exchanger unit 16 can be located between the two heat exchanger units 12, 14 or, for example, also be arranged at the edge region of the ram air channel 40. The arrangement of the heat exchanger units 12, 14, 16 is arbitrary. The heat exchanger units 12, 14, 16 form the heat exchanger 10.

Downstream of the heat exchanger in the ram air outlet 44, the blower 50, 52 are arranged, which are also referred to in the figures with the short names ERAF 1 and ERAF 2. The fans 50, 52 are driven by an electric motor.

As can be seen from FIG. 1, the blowers 50, 52 are located in flow-mechanically through walls of separate portions of the ram air outlet channel 44. Between these sections is the blower bypass 60, which serves to increase the permeability during the flight. Downstream of the blower 50, 52 and in the outlet of the bypass channel 60 are the check valves 54, 56 and 58th

On the inlet side of the ram air inlet channel 42 is the ram air channel inlet flap 43 (Duplex RAIA).

The shaft means communicate with the water separation circuits 70, 80. These consist in known manner of a reheater (REH), a condenser (CON) and a water separator (WE).

The reheaters (REH) communicate with the outlet sides of the heat exchanger units 12, 14. In the connecting lines are measuring elements (Venturi) for measuring the volume flow of the heat exchanger units 12, 14 leaving air.

As is further apparent from FIG. 1, bypass lines 120, 130 are provided, which extend from the outlet side of the heat exchanger units 12, 14 to the turbine outlet side and which can be shut off by means of a valve 122, 132 (BPV) arranged therein.

In order to avoid or limit any icing on the turbine outlet side or in the condenser (CON), a bypass line is furthermore provided, which extends from the compressor outlet side to the turbine outlet side and which is provided with a valve (AIV = anti-icing device). Valve) can be shut off.

The operation of the air conditioning system shown in Fig. 1 is as follows:

The compressors 22, 32 are subjected to ambient or ram air. The compressor power is applied on the one hand by the turbines 24, 34 and in addition by the electric motors 26, 36. These components together each form one of the shaft devices 20, 30. The compressed air flows separately into one of the heat exchanger units 12, 14 arranged in the common ram air channel 40 and is cooled therein by means of the congestion or ambient air guided into the ram air channel 40.

The air cooled in this way, after passing through the flow meter (Venturi), enters the reheater (REH) and then the condenser (CON), where most of the moisture in the air is condensed out. The condensed water is separated in the water separator (WE). The air is then passed through the reheater, while slightly heated and then relaxed in the turbines 24, 34. The air is strongly cooled. The cooled air in this way is used to cool the condenser (CON) and is slightly heated. It then passes through a check valve in a mixing chamber or in the passenger cabin.

This operating mode, which is used in particular in ground operation and at lower altitudes, is shown in FIG. 3a.

The cooling of the heat exchanger units 12, 14 supplied air via accumulation or ambient air, which flows after passing through the adjustable ram air inlet flap 43 into the ram air inlet channel 42 and then flows through the heat exchanger units 12, 14, 16.

Downstream of the heat exchanger units 12, 14, 16 there are blowers 50, 52, which are arranged in fluid-mechanically separate subregions of the ram air outlet channel 44. It is provided that the fluidic separation of the ram air outlet channel 44 does not take place in the area adjoining the heat exchanger 10, but downstream therefrom. Compared to a continuous fluid-mechanical separation of the ram air outlet channel 44, this has the advantage that even if one blower 50, 52 fails, the other blower can convey air through all the heat exchanger units 12, 14, 16.

The blowers 50, 52 are driven by an electric motor and serve in ground operation for the promotion of ambient air through the ram air duct 40. In flight, the flow through the ram air duct 40 due to the back pressure. In order to increase the permeability of the system, the bypass channel 60 is provided.

To ensure the flow through the heat exchanger 10 and to prevent backflow, the check valves 54, 56, 58 are provided on the outlet side in the end region of the ram air outlet channel 44.

At higher altitudes, according to the mode of operation illustrated in FIG. 3b, the valves 122, 132 are opened in order to ensure a bypass of the water separation circuit 70, 80 and the turbines 24, 34 by means of the bypass lines 120, 130. In this case, the cooling is not done by means of the turbines 24, 34, but by means of the heat exchanger units 12, 14, through which the air after its compression in the compressors 22, 32 flows. On the outlet side, the air is then guided via the bypass lines 120, 130 into the outlet lines of the turbines 24, 34 or into the inlet lines of the mixing chamber or the passenger cabin. At high altitudes, the cooling without the use of the turbines 24, 34 may be sufficient because the supplied ram air is very cold.

Due to the bypass of the turbines 24, 34, the drive of the compressors 22, 32 takes place in this operating mode exclusively with the aid of the motors 26, 36.

FIG. 2 shows two of the air conditioning systems according to FIG. 1 with the designations (AGU1 and AGU2). FIG. 2 further shows the mixer chamber upstream of the passenger cabin, into which the outlet air of the air conditioning system according to FIG. 1 is directed. The system according to FIG. 2 thus contains 4 equivalent fresh air feeds.

Further apparent from Fig. 2 are the cabin air circuits 100, by means of which air is discharged from the cabins by means of a blower, cooled and then fed to the mixing chamber. The cabin air circuits 100 each include an evaporator 110, which forms a component of a coolant circuit together with the designed as a condenser heat exchanger units 16. In this case, it is provided that the coolant evaporates in the evaporator 110 and thereby withdraws heat from the circulated cabin air heat. The vaporized coolant is condensed in the heat exchanger unit 16 and gives off heat to the ram air flow passing through the ram air passage 40.

As further shown in FIG. 2, electrical heaters may be provided between the mixing chamber and the cabin to bring the cabin air to the desired setpoint according to the different cabin requirements.

From Fig. 1 and 2 it follows that the entire air conditioning system without bleed air from the engines or from an auxiliary unit manages. Both the The fresh air supplied to the cabin as well as the air conducted for cooling by the ram air duct consists exclusively of ambient or ram air in this exemplary embodiment.

The shaft means may be arranged parallel to each other. The ram air channel may be located between the shaft devices. In the area adjacent to the ram air inlet channel, the ram air or ambient air inlets for the shaft devices may be located.

The heat exchanger units can be arranged next to one another in the flow direction or else one above the other. Furthermore, it is possible to make the connection of the shaft means to the heat exchanger units laterally or below the heat exchanger units. Of course, reverse arrangements with above the heat exchanger units arranged shaft means are conceivable. Further, it is also possible, as required, the shaft means and the heat exchanger units are not perpendicular to each other, but deviating to arrange for example at a 45 ° angle.

As can be seen from FIGS. 1 and 2, the main components of each fresh air flow path to be treated are the motorized shaft assembly, the heat exchanger unit, a water separation circuit, the by-pass bypass line, the anti-icing valve, and the flow meter.

The common components of the fresh air paths are the ram air duct inlet flap, the ram air duct with check valves, the electrically operated blowers, the cooling system for the recirculated cabin air and a control unit.

In order to ensure optimum cabin temperature control, the electric heating devices illustrated in FIG. 2 may be provided, wherein a heating device may be provided per cabin area. In addition, it can be provided that hot compressed air is branched off downstream of the compressor.

This air is then mixed via valves with the cold air flowing from the mixing chamber into the passenger cabin.

The temperature increase of the fresh air required for the heating operation is achieved by the compression in the compressors. As stated above, additional electrical heaters can be used.

The temperature control of the overall system via the corresponding change in the operation of the blower 50, 52 (in ground operation), on the open position of the ram air duct inlet flap 43, via the electric heaters and by means of the cooling of the circulated cabin air.

In order to prevent or limit any icing, it may be provided that the corresponding valve AIV is temporarily opened in order to guide hot compressor outlet air into the outlet area of the turbines.

Fig. 4 shows a schematic representation of an air conditioning system according to the invention with use of the cabin exhaust air. In airplanes, the cabin is printed in flight in order to reach the necessary environmental conditions for the people. Due to the decreasing with the altitude ambient pressure, the difference between cabin pressure and ambient pressure increases with increasing altitude. The cabin air is directed to the ambient air by being uselessly expanded via the valves.

It has therefore been proposed to provide a system for using cabin exhaust air (Cabine Air Recovery (CAR)), by means of which the energy content of the cabin exhaust air is used. The cabin exhaust air is first released via a turbine and then forwarded to the environment. The resulting power can z. B. can be used directly to drive a compressor or for power generation by means of a generator.

Fig. 4 shows the use of such a system in an air conditioning system according to the present invention. As can be seen from FIG. 4, the cabin exhaust air can be led through a corresponding connection line to the inlet side of the turbine T. This line can be shut off by means of the valve CSOV (cabine shut off valve). When operating Cabine Air Recovery at higher altitudes, this valve is opened to direct the cabin exhaust air into the turbine T.

In the connecting line between the Wasserabscheidekreislauf and the turbine inlet is the shut-off valve TSOV (turbine shut off valve). The Turbine outlet line also contains the Check Valve (CKV). This valve is located upstream of the mouth of the bypass line in the turbine outlet, as shown in FIG. 4. The valves TSOV and CKV are closed during Cabine Air Recovery to prevent the mixing of fresh air with the exhaust air.

From the turbine outlet line branches off a line in which the valve ASOV (ambient shut off valve) is arranged. This valve is opened during Cabine Air Recovery, which directs the turbine outlet air into the environment and not into the condenser CON or into the mixing chamber.

In the operating mode shown in Fig. 4, in which the compressed air in the compressor C is supplied via a turbine bypass of the mixing chamber, the turbine T can be used for the Cabine Air Recovery. In this case, cabin air flows via the open valve CSOV into the turbine, where it is expanded and discharged via the outlet line with the open valve ASOV to the environment. The closed valves TSOV and CKV prevent a mixture of the exhaust air from the cabin with the fresh air supplied to the cabin.

As shown in Fig. 4, such a system is provided for each of the wave devices MACM.

The available shaft power from the relaxation of the cabin exhaust air via the turbine T increases with the altitude. This corresponds to the requirements for the compression, which also increase with the altitude, as there is a greater pressure difference between the cabin and the environment.

FIG. 2 shows an embodiment of the invention in which two heat exchanger units MHX 1, MHX 2 are combined in a ram air duct per air conditioning system (AGU 1, 2). The resulting obvious system configurations are thus 2 or 2 + 2 or 2 + 2 + 2 etc. heat exchanger units.

However, the invention is not limited to two heat exchanger units per ram air channel or per AGU. Rather, three or more than three heat exchanger units can be provided. In principle, it is also conceivable that only one heat exchanger unit, i. a heat exchanger is provided.

The present invention may basically be embodied with one or two or more heat exchangers. It can be provided that each of these heat exchangers is arranged in a separate ram air channel. It can be provided that each of the heat exchanger is connected to the compressed air side with a shaft device. It is also conceivable that two or more than two heat exchangers are arranged in a ram air channel.

5 shows a corresponding architecture, in which the ram air heat exchanger consists of three heat exchanger units separated on the compressed air side, each of which communicates with one of the shaft devices MACM on the compressed air side, as can be seen from FIG. Fig. 5 shows an architecture with three wave devices MACM. In addition to such an architecture, of course, systems with more than three ram air heat exchanger units in the ram air duct are also conceivable. Accordingly, more than three shaft devices can be used. The wave devices associated with the heat exchanger units may be identical or different from each other. Fig. 5 shows a system with three identical wave devices or identical interconnections the wave devices. The compressors of the shaft devices are supplied with congestion or bypass air. After compression, the air is supplied to the compressed air side of the heat exchanger units. Subsequently, in a Wasserabscheidekreislauf the deposition of water. The thus dehumidified air is released in the turbine and then fed to the cabin or a mixing chamber. As can also be seen from FIG. 5, all three shaft devices are designed with a turbine bypass, which can be closed by means of the valve BPV and which connects the compressed-air-side outlet of the heat exchanger units to a connecting line between the condenser and the mixing chamber or the cabin.

Claims (29)

1. Air-conditioning system, in particular an air-conditioning system for air-conditioning of a passenger cabin in an aircraft, having at least, one heat-exchanger (10) which is arranged in a ram-air channel (40), having at least one shaft device (20,30) which is connected on the compressed-air side to the heat-exchanger (10), has at least one compressor (22,32) to whose inlet side the ram-air or external air is applied, and has at least one turbine (24,34), having at least one motor (26,36) for driving the compressor, having a turbine bypass line (120,130) for bypassing the turbine on the compressed-air side, and having at least one control device by means of which the air-conditioning system can be operated in a first operating mode in which the compressed air is expanded in the turbine (24,34), and can be operated in a second operating mode in which the majority or all of the compressed air is passed through the turbine bypass line (120,130), with the control device being connected to the motor (26,36) and being designed such that, in the first operating mode, the motor is operated in such a way that the motor power is used for cooling purposes and for forcing air to flow and, in the second operating mode is operated in such a manner that the motor power is used for compression of the ram-air or external air,
   characterized
   in that the turbine is preceded by a water separator (WE), and the turbine bypass line (120,130) bypasses both the water separator (WE) and the turbine on the compressed-air side.
2. Air-conditioning system according to Claim 1, characterized in that the control device is designed such that the first operating mode is used in ground operation and/or at low altitudes, and the second operating mode is used at altitudes higher than this.
3. Air-conditioning system according to one of the preceding claims, having at least one heat-exchanger (10), which is arranged in a ram-air channel (40), for cooling compressed air, and having at least one first and one second shaft device (20,30), with the heat-exchanger (10) comprising at least one first and one second heat-exchanger unit (12,14), with the second heat-exchanger unit (14) being separated from the first on the compressed-air side, which heat-exchanger units (12,14) are arranged in the common ram-air channel (40) and each of which is connected on the compressed-air side to a respective one of the shaft devices (20,30), with the shaft devices (20,30) having compressors (22,32) which are respectively connected on the outlet side to the inlet of the heat-exchanger units (12,14) on the compressed-air side, with ram-air or external air being applied to the inlet side of the compressors (22,32), and in that one or more motors (26,36) are provided, by means of which the compressors (22,32) can be driven.
4. Air-conditioning system according to Claim 3, characterized in that the heat-exchanger units (12,14) form a physical unit.
5. Air-conditioning system according to Claim 3 or 4, characterized in that a common ram-air inlet channel (42) is provided for the at least two heat-exchanger units (12,14).
6. Air-conditioning system according to Claim 5, characterized in that a variable-position ram-air channel inlet valve (43) is provided in the ram-air inlet channel (42).
7. Air-conditioning system according to one of Claims 3 to 6, characterized in that a common ram-air outlet channel (44) is provided for the at least two heat-exchanger units (12,14).
8. Air-conditioning system according to one of Claims 3 to 7, characterized in that one, two or more motor-driven fans (50,52) is or are provided in the ram-air outlet channel (44).
9. Air-conditioning system according to Claim 8, characterized in that non-return valves (54,56) are provided downstream from the fans (50,52).
10. Air-conditioning system according to one of the preceding claims, characterized in that one or more fan bypasses (60) which are provided with a non-return valve (58), are arranged in the ram-air outlet channel (44).
11. Air-conditioning system according to one of the preceding claims, characterized in that the compressors (22,32) are multistage compressors, with ram-air or external air being applied to the inlet side of the first stage (22a,32a) and with the outlet side of the last stage (22b,32b) being connected to the inlet on the compressed-air side of the heat-exchanger units (12,14).
12. Air-conditioning system according to one of the preceding claims, characterized in that the shaft devices (20,30) have at least one compressor (22,32), turbine (24,34) and motor (26,36).
13. Air-conditioning system according to one of the preceding claims, characterized in that each of the shaft devices (20,30) is connected to a respective water separation circuit (70,80).
14. Air-conditioning system according to one of the preceding claims, characterized in that the heat-exchanger (10) has a further heat-exchanger unit (16) to which ram-air or external air can be applied and which is not connected on the compressed-air side to the first and the second heat-exchanger unit (12,14).
15. Air-conditioning system according to one of the preceding claims, characterized in that a cabin air circuit (100) is provided in which means are arranged for dissipation of heat from the circulating air.
16. Air-conditioning system according to Claim 15, characterized in that the means comprise a heat-exchanger.
17. Air-conditioning system according to Claim 15, characterized in that the means comprise an evaporator (110).
18. Air-conditioning system according to Claims 14 and 17, characterized in that the further heat-exchanger unit (16) which is arranged in the ram-air channel is in the form of a condenser and is connected to the evaporator (110), with the heat-exchanger unit (16) and the evaporator (110) being components of a coolant circuit.
19. Air-conditioning system according to one of the preceding claims, characterized in that one or more bypass lines (120,130) are provided, which extend from the outlet side of the heat-exchanger units (12,14) to the outlet side of the turbines (24,34) and can each be shut off by means of a valve (122,132) arranged in them.
20. Air-conditioning system according to one of the preceding claims, characterized in that the inlet side of the turbine (T) is connected via a line which can be closed by a valve (CSOV) to the cabin or to a mixing chamber connected upstream of it, and is connected on the outlet side via a line which can be closed by a valve (ASOV) to the environment, and in that means are provided by means of which the turbine (T) can be shut off from the lines which carry the air which has been compressed in the compressor (C).
21. Air-conditioning system according to Claim 20, characterized in that the means are in the form of valves (TSOV,CKV) which are arranged in the inlet line, which connects the turbine (T) to the water separation circuit, and in the outlet line, which connects the turbine (T) to the mixing chamber or the cabin.
22. Method for conditioning of air for air-conditioning of an area, in particular for air-conditioning of a passenger cabin of an aircraft, comprising the following steps:

    - compression of ram-air or external air in a compressor unit (22,32) which is driven by means of a motor (26,36), and supply of the compressed air to a heat-exchanger (10),

    - cooling of the air supplied to the heat-exchanger (10) by means of ram-air or external air,

    - with the air which has been cooled in the heat-exchanger (10) being supplied, in a first operating mode, to a water separator (WE) and being expanded in an expansion stage (24,34),

    - with the majority or all of the air which has been cooled in the heat-exchanger (10) being passed, in a second operating mode, in the bypass (120,130) around the water separator (WE) and the expansion stage (24,34),

    - and with the motor power being used for cooling purposes and for forcing air to flow in the first operating mode, and the motor power being used for compression of the ram-air or external air in the second operating mode.
23. Method according to Claim 22, comprising the following steps:

    compression of external air or ram-air in a first motor-driven compressor unit (22) and for supplying the compressed air to a first heat-exchanger unit (12) of a heat-exchanger (10);

    compression of external air or ram-air in a second motor-driven compressor unit (32) and for supplying the compressed air to a second heat-exchanger unit (14), which is separated on the compressed-air side from the first heat-exchanger unit (12) of the heat-exchanger (10), and

    cooling of the air supplied to the heat-exchanger units (12,14), by means of ram-air or external air;

    with the air which has been cooled in the heat-exchanger units (12,14) being supplied, in a first operating mode, to a water separation circuit (70,80), being expanded in an expansion stage (24,34) and being passed to the area to be air-conditioned or to an upstream mixing chamber,

    and with the air which has been cooled in the heat-exchanger units (12,14) being passed, in a second operating mode, directly to the area to be air-conditioned or to an upstream mixing chamber, bypassing the water separation circuit (70,80) and the expansion stage (24,34).
24. Method according to Claim 23, characterized in that the first operating mode of the method is used during ground operation of the aircraft and at low aircraft altitudes, and the second operating mode is used at altitudes higher than this.
25. Method according to Claim 23 or 24, characterized in that the cooling power for cooling of the air which is supplied to the heat-exchanger units (12,14) is controlled or regulated by ram-air or external air by varying the position of a ram-air channel inlet valve (43) and/or by varying the power of fans (50,52) which are arranged in the ram-air outlet channel (44).
26. Method according to one of Claims 23 to 25, characterized in that at least a portion of the air in the area concerned, in particular in the cabin air, is circulated and is cooled in the process.
27. Method according to Claim 26, characterized in that the cooling is carried out by means of a cooling medium which is circulated, and in that heat is extracted from the cooling medium in a heat-exchanger unit (16) which is arranged in the ram-air channel (40) of the air-conditioning system.
28. Method according to one of Claims 23 to 27, characterized in that, in the second operating mode, cabin outlet air is expanded in the turbine (T) and is then supplied to the external air.
29. Method according to one of Claims 22 to 28, with more than 50% of the available motor power being used for cooling purposes and for forcing air to flow in the first operating mode.

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